1. Field
This disclosure relates to the placement of subtitles on stereoscopic imagery.
2. Description of the Related Art
It is well known that stereoscopic motion and still imagery may be obtained by the capture of what is called the stereoscopic image pair. The stereoscopic image pair is constituted by two images of an object or scene, taken from different points of view such that each of the two points of view (or eyes) of the pair creates an image from the perspective of the what would be seen by the right or left eye respectively of a person viewing the scene from that particular point of capture. When the stereoscopic image pair is viewed using a system that presents each of the two images of the image pair to the viewer in such a way that each of the viewer's eyes sees only that image corresponding to the respective eye; left to left, right to right; the illusion of three-dimensional depth is created. Such systems have been described in U.S. Pat. No. 542,321, U.S. Pat. No. 2,122,649, U.S. Pat. No. 2,309,879, U.S. Pat. No. 2,463,311, U.S. Pat. No. 2,511,334 and U.S. Pat. No. 2,570,654.
Common practice for the subtitling of stereoscopic motion and still imagery has been to imprint subtitles upon both the left and right images of the stereo image pairs or to imprint subtitles on areas completely exterior to the image frame, such as separate title cards or areas of the medium upon which the image pairs are printed which are separate and distinct from the areas within which the actual images themselves are printed.
When imprinting subtitles within the image area of both eye views of a stereo pair of stereoscopic motion or still imagery prior to exhibition, or when separately projecting the subtitles onto the left and right eye views at exhibition time, much care must be taken in the placement of these subtitles in order to prevent misalignment of the two projected views of the subtitle. Such misalignment has been shown to cause discomfort to the viewer if there is even a slight placement error between the left and right eye subtitles. In addition the placement of these stereo subtitles must be done in such a fashion as to not create occlusions or interference with the main imagery which would obscure such portions of the imagery as are necessary to provide depth cues to the viewer and in so doing, eliminate the illusion of three-dimensional depth.
It is well known that text graphic characters and elements may be imprinted directly on film utilizing systems and methods such as those described in U.S. Pat. No. 5,367,348 or may be separately projected from a film print or digital file containing only subtitles in synchronicity with the motion picture images and sound track utilizing systems and methods such as those described in U.S. Pat. No. 6,741,323 B, U.S. Pat. No. 6,046,778, and U.S. Pat. No. 4,673,266. Text, graphic characters and elements may also be composited onto digital files utilizing computer software. These digital files may then be printed onto paper, film stock or other medium, or they may be assembled into sequences of one or more stereo pairs and viewed utilizing a digital system containing one or more projectors or displays.
Subtitles may be stored as part of a digital motion imagery file which is stored on a suitable device and in such a suitable format that said digital file may be projected utilizing digital projection devices or may be viewed utilizing video devices. Such a digital file may correspond to a Digital Cinema Initiative Distribution Package (DCP) as taught by Digital Cinema Initiatives, LLC's “Digital Cinema System Specification”.
Throughout this description, elements appearing in figures are assigned three-digit reference designators, where the most significant digit is the figure number and the two least significant digits are specific to the element. An element that is not described in conjunction with a figure may be presumed to have the same characteristics and function as a previously-described element having a reference designator with the same least significant digits.